1. Field of the Invention
The present invention relates to machine tools, and more particularly to a machine tool having the function of correcting a mounting error through contact detection.
2. Description of Related Art
As techniques for detecting inclination of a workpiece to be cut by a cutting machine, there has been known a technique in which a displacement detector is brought into contact with a reference plane of the workpiece or of a machining attachment and then the reference plane is traced with the displacement detector to acquire data about the inclination. According to this technique, the rotary axis on which the workpiece or the machining attachment is mounted is manually moved in accordance with the acquired data, by using the operator's panel or the like, to adjust the orientation of the workpiece. After the adjustment, the displacement detector is again brought into contact with the reference plane of the workpiece or machining attachment to ascertain whether the mounting error of the workpiece or machining attachment has become smaller than an allowable value or not. If the mounting error is greater than the allowable value, the adjustment is repeated until the mounting error becomes smaller than the allowable value (cf. Examined Japanese Patent Publication No. H06-26787).
This technique requires, however, an additional measuring instrument serving as the displacement detector, such as an electric micrometer, and moreover, the accuracy in and the time required for the orientation correction greatly vary from operator to operator. Also, where the surface of a brittle material needs to be directly traced in order to position the material in parallel with a machining surface, there is a possibility that linear scars are left on the surface of the brittle material.